Linux中 帮助命令

一 帮助命令man

1、语法

man 命令

获取指定命令的帮助。

2、举例

man ls

查看ls的帮助。

 

二 man的级别

 

查看命令拥有哪个级别的帮助

man -f 命令

whatis 命令

 

三 查看和命令相关的所有帮助

man -k 命令

相当于

apropos 命令

例如

apropos passwd

 

三 实战

[root@localhost test]# man ls

[root@localhost test]# man man

[root@localhost test]# man -f ls

ls (1) - list directory contents

ls (1p) - list directory contents

[root@localhost test]# man -f passwd

sslpasswd (1ssl) - compute password hashes

passwd (1) - update user's authentication tokens

passwd (5) - password file

[root@localhost test]# man 1 passwd

[root@localhost test]# man 5 passwd

[root@localhost test]# whereis passwd

passwd: /usr/bin/passwd /etc/passwd /usr/share/man/man1/passwd.1.gz /usr/share/man/man5/passwd.5.gz

[root@localhost test]# man 5 passwd

[root@localhost test]# whatis ls

ls (1) - list directory contents

ls (1p) - list directory contents

[root@localhost test]# man -f null

null (4) - data sink

[root@localhost test]# man 4 null

[root@localhost test]# whereis ifconfig

ifconfig: /usr/sbin/ifconfig /usr/share/man/man8/ifconfig.8.gz

[root@localhost test]# apropos passwd

chpasswd (8) - update passwords in batch mode

fgetpwent_r (3) - get passwd file entry reentrantly

getpwent_r (3) - get passwd file entry reentrantly

gpasswd (1) - administer /etc/group and /etc/gshadow

grub2-mkpasswd-pbkdf2 (1) - Generate a PBKDF2 password hash.

lpasswd (1) - Change group or user password

lppasswd (1) - add, change, or delete digest passwords.

pam_localuser (8) - require users to be listed in /etc/passwd

passwd (1) - update user's authentication tokens

sslpasswd (1ssl) - compute password hashes

passwd (5) - password file

passwd2des (3) - RFS password encryption

pwhistory_helper (8) - Helper binary that transfers password hashes from passwd or shadow to opasswd

saslpasswd2 (8) - set a user's sasl password

smbpasswd (5) - The Samba encrypted password file

smbpasswd (8) - change a user's SMB password

[root@localhost test]# man -k passwd

chpasswd (8) - update passwords in batch mode

fgetpwent_r (3) - get passwd file entry reentrantly

getpwent_r (3) - get passwd file entry reentrantly

gpasswd (1) - administer /etc/group and /etc/gshadow

grub2-mkpasswd-pbkdf2 (1) - Generate a PBKDF2 password hash.

lpasswd (1) - Change group or user password

lppasswd (1) - add, change, or delete digest passwords.

pam_localuser (8) - require users to be listed in /etc/passwd

passwd (1) - update user's authentication tokens

sslpasswd (1ssl) - compute password hashes

passwd (5) - password file

passwd2des (3) - RFS password encryption

pwhistory_helper (8) - Helper binary that transfers password hashes from passwd or shadow to opasswd

saslpasswd2 (8) - set a user's sasl password

smbpasswd (5) - The Samba encrypted password file

smbpasswd (8) - change a user's SMB password